Medical devices for injecting or infusing liquid medications, and including devices for withdrawing patient body fluids typically use a hypodermic needle that is inserted into the patient's body. For example, an infusion device commonly used is a Huber needle that is adapted for insertion in a permanent medical site on a patient to administer liquid medications.
A common concern associated with use of medical needles is avoidance of inadvertent needle stick injuries following removal of a needle from the patient in order to prevent, for example, transfer of microbial contaminants and infectious diseases. Various safety features have been proposed to prevent contact with the needle following a clinical procedure, such as providing a separate sheath member that may be placed over the needle and providing a collapsible or movable sheath structure that can extend to cover and remain over the needle at the end of a procedure. Exemplary safety devices for use on medical needles are disclosed in U.S. Pat. Nos. 5,336,199 and 7,083,600.